title: Depolarization-induced suppression of spontaneous release in the avian midbrain.
abstract: Spontaneous neurotransmitter release has been considered synaptic noise for decades. Recent work, however, suggests that synaptic events arising from action potential (AP)-independent neurotransmitter release contribute to synaptic function in a manner qualitatively different from AP-dependent release. We investigated the effect of somatic depolarization on spontaneous neurotransmitter release in neurons of the external portion (EX) of the chicken inferior colliculus. We found this manipulation affects spontaneous but not AP-dependent release onto EX neurons in a retrograde manner. This depolarization-induced suppression of spontaneous release requires activation of NMDA receptors on the presynaptic cell and postsynaptic calcium-dependent vesicle fusion. These results show a novel form of plasticity that allows the postsynaptic cell to selectively modulate spontaneous neurotransmitter release of its afferent inputs.
authors.affiliation: Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Mario Alexander
authors.initials: MA
authors.lastname: Penzo
authors.forename: José Luis
authors.initials: JL
authors.lastname: Peña
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002645:Chickens; D004594:Electrophysiology; D005260:Female; D007245:Inferior Colliculi / Q000187:drug effects / Q000502:physiology*; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2